Police are investigating the suspected sabotage of ovitraps in Wong Tai Sin. The Food & Environmental Hygiene Department said today its officers found 14 of the district's 62 ovitraps had been tampered with in the last month.

No irregularities have been detected in other districts.

The department reminded people not to tamper with ovitraps as they are important devices that monitor the breeding of Dengue vectors.

May ovitrap index rises

The monthly average ovitrap index rose from 7.6% in April to 15.1% in May. All 38 areas surveyed last month recorded positive indices ranging from 2% to 31.5%.

Twelve areas hit the alert zone of 20% to 40%. They are Lam Tin (31.5%), Tuen Mun North (30.5%), Kwai Chung (28.3%), Happy Valley (27.8%), Pokfulam (27.8%), Sheung Shui (27.3%), Fanling (23.6%), Tin Shui Wai (22.2%), Cheung Sha Wan (21.4%), Tsim Sha Tsui (21.1%), Yuen Kong (20.8%) and Wong Tai Sin Central (20.8%). The inter-departmental anti-mosquito response mechanism has been activated in these districts.

The index for port areas also rose from 0.9% in April to 1% in May.